This instrument's acoustic design produces a rich and warm sound with excellent projection, while the ergonomic design provides optimum balance and hand positioning . Double main tuning slides make it easy to tune, even in extreme conditions. Key of Bb, .562" bore, 11" bell, nickel-plated pistons, adjustable 1st and 3rd slides, clear lacquer finish, 7.5 lbs., large shank mouthpiece receiver, Helleberg 5E mouthpiece, heavy-duty stackable case.